Brewed up an IPA on Sunday. OG 1.056. Used Cry Havoc yeast (WLP862). Pitched it without a starter at about 68 degrees. I live in Hawaii where it is pretty warm. Kept my primary fermenter (i.e., plastic bucket type) in an ice bath and added ice two times per day. Temperature of ice bath ranged from low 60s to 75 when I checked. Got vigorous fermentation for a few days, but it stopped as of today. (At least I think it did. I don't have the patience to stand and stare at the air lock.) Tasted beer today. Tasted sweet. SG was 1.024 (corrected). Target SG is 1.013. Was thinking about going to local homebrew store tomorrow, picking up a vial of California Ale yeast (WLP001) and pitching it tomorrow afternoon. Is this the right thing to do? Do I need to have more patience. Will take Charlie Papazian's advice for now: "Relax, have a homebrew."

If the temperature drops more than a couple degrees during fermantation, especially later in fermentation, the yeast can sometimes drop out early. You want to keep the temperature steady.

At this point, the first thing I would try would be letting the fermenter warm up. This may get the yeast to restart and finish the fermentation, if there is more sugar that they can ferment. If that doesn't work, it's also possible that a more aggressive yeast like WLP001 or US-05 might be able to chew off a few more points. It can be difficult to restart a stuck fermentation, though.